Abstract

This paper aims to investigate the dispersion process of aqueous suspensions with crystalline nanocellulose (NCC) for the production of cementitious composites reinforced with crystalline microcellulose (MCC) and polypropylene fibers (FPP). Initially, aqueous solutions with nanocellulose with different levels of surfactant were characterized in terms of dispersion quality through dynamic light scattering, zeta potential and UV-Vis spectroscopy, aiming to determine the ideal surfactant content. Subsequently, the aqueous suspensions were added to the cement/sand mixture to prepare the composites. The properties in the fresh and hardened states were investigated for each addition level. The optimal content of Pluronic to disperse the nanocellulose was 40% in relation to its mass. The results showed a reduction in the workability of the samples. In terms of mechanical performance, the composites of recipe 1 (0.3% FPP, 0.5% MCC and 0.3% NCC) showed increases of around 17% in compressive resistance at 56 days, 18% in elasticity modulus and around 7% in tensile strength in flexion at 28 days.

Keywords:
Crystalline nanocellulose dispersion; Polypropylene fibers; Crystalline microcellulose; Cementitious composites; Mechanical properties